As safe as houses
October 1st 2007 Machine operators across the UK are continually
being placed in danger due to failure of
companies to adhere to new risk assessment
legislation. Brick manufacturer, Baggeridge Brick learnt
how to cost effectively make its work environment
safer without interrupting production
Baggeridge Brick, one of the UK's largest brick
manufacturers, had identified a problem on its 'dryer car'
operation, responsible for the movement of wet brick
palettes into drying and firing chambers. The car itself
moves on rails at speeds of up to 15mph and had no
perimeter safety guarding to protect entrance into the
hazard area.
Dennis Brittle, group engineer at Baggeridge Brick, was
concerned about the health and safety risk: "The dryer car
runs at substantial speeds once
operated and passers-by were
being placed in significant risk
due to the lack of perimeter
guarding. This has been a problem
for us for a number of years and
with the new safety standards
EN62061 and EN13849 being
adopted across Europe and the UK,
and the move to fully automatic
operation (no driver) we felt we
had to find a suitable and safe
solution."
The second problem lay within
the car's ability to move between
operational zones within the plant. Each area demands a
different level of safety protection, but the 'outdated'
system failed to monitor those workers entering and
leaving the zones at any one time. Operators were placed
in hazardous circumstances which could have led to risk of
injury.
Brittle continued: "We had absolutely no way of
monitoring the operational zones within the plant, there
were no security codes in place and the zones were easily
accessible to any member of staff. Workers could gain
access to these highly hazardous areas and we would be
unable to guarantee their safety".
Industry specialist, Siemens Automation and Drives was
brought in to provide a safety design solution which would
actively reduce the risk of injury.
Parmley Graham, a Siemens integrator in the Midlands,
was presented with the initial specification, which
contained two strict requirements. Firstly, integrate a new
safety system into the 'dryer car' to prevent accidents and
provide greater levels of zone security. Secondly, ensure
the installation provides no disruption to overall working
and production targets.
Brittle highlighted: "We needed a completely versatile
system which would enable us to monitor the safety of the
dryer car operator and at the same time ensure zone
security and safety by limiting entrance to pre-determined
personnel as per the requirements of our risk assessment."
Siemens engineered a solution involving ASiSafe,
standard Asi control and an S7 PLC.
Paul Hingley, product manager for communications at
Siemens, says:
"The system provided for Baggeridge Brick had to tick a
number of very important boxes. The system needed to offer
full diagnostic capability to monitor any change in the dryer
car or additional machinery programming. The system also
had to offer advanced override safety facilities, operators
could only gain safe entrance into the various operational
zones.
"In addition Baggeridge Brick were specific in their
requirement for a virtually maintenance free piece of
equipment. The ASiSafe system has various levels of selfmonitoring
providing instant diagnostic information via the
PLC and has the flexibility to be re-programmed as
necessary by the various 'security cleared' operators.
"Together with Parmley Graham we have supplied a
completely integrated control and safety solution on one
network. This provides ease of installation and the ability to
construct complex safety control logic, whilst at the same
time reducing the administrative downtime previously
needed to monitor and programme the equipment."
The entire system was retrofitted into the plant and
complete on-site training was provided following
installation.
Brittle concluded: "The Siemens ASi and ASiSafe system is
completely versatile and was easily integrated into our
existing working processes. We are now fully compliant with
the safety category required by our risk assessment and are
happy in the knowledge that our machine operators are
being monitored 24hr a day by Siemens AsiSafe." More articles from Siemens Moore Process Automation: | 
